You have no idea how much I would love to explore Canada using my own vehicle! Apparently it is really cold back home as well. These Aussie cockroaches wouldn't stand a chance in cold like that. They would bolt at the first mention of the word cold. Ha, maybe I'll ship it over and customs can clean my car for me. They wouldn't even let it in!
The bug bomb was the first thing I thought of, but upon further research there is risks of ruining the plastics, explosions/fire from shorts or sparks and I am concerned about the leather. I have been instructed to is surface spray and spray all the little tight areas and seal it up overnight. Work on the same idea as the bug bomb but I am controlling it. I also like that silica powder earth stuff and sprinkle it all over the carpet. I will see how it goes